Building structure



FIG. 1 is a perspective view of a building structure showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof, the left and right elevational views being the same as said rear elevational view; and,

FIG. 4 is a top plan view thereof. 

I claim the ornamental design for the building structure, as shown and described. 